My present invention relates to a circuit configuration that can be used to realize tunable components such as but not limited to, bandstop filters, bandpass filters and negative resistance amplifiers that are capable of having very narrow bandwidths or very wide bandwidths depending on the configuration. It should be understood that a filter with a percent bandwidth of less than about 15% is considered narrow band and that a filter with a percent bandwidth of less than about 5% is considered very narrow bandband. Thus a filter with a 20 MHz. bandwidth centered at 100 MHz is not narrow band but a filter with a 20 MHz bandwidth centered at 1 GHz is very narrow band. The use of the term narrow band or wide band when used will refer to the percent bandwidth.
There are already known circuits where the tuning method involves changing the capacitance of resonators by either using voltage variable capacitors or by the use of switching matrices that switch different capacitors into the circuit.